High School

What is the pH of solution containing 2.3x10⁻² molL⁻¹ of H⁺ ions?

A. -2.3
B. -1.64
C. 2.3
D. 1.64

Answer :

To find the pH of a solution, we use the formula:

[tex]\text{pH} = -\log [\text{H}^+][/tex]

where [tex][\text{H}^+][/tex] is the concentration of hydrogen ions in moles per liter (mol L⁻¹).

In this case, the concentration of [tex]\text{H}^+[/tex] ions is [tex]2.3 \times 10^{-2} \text{ mol L}^{-1}[/tex].

Let's calculate the pH:

[tex]\text{pH} = -\log(2.3 \times 10^{-2})[/tex]

Calculating this using a calculator, we get:

[tex]\text{pH} \approx 1.64[/tex]

Therefore, the pH of the solution is approximately 1.64.

So, the correct answer is D. 1.64.

The pH scale is a measure of the acidity or basicity of an aqueous solution. It typically ranges from 0 to 14, with 7 being neutral. A pH less than 7 indicates an acidic solution, which is consistent with our result here, confirming that the solution is acidic.